Process for making engine cylinders with an inner lining



A. LEISAGE July 18,- 1939.

PROCESS FOR MAKING ENGINE CYLINDERS WITH AN INNER LINING Filed Feb. 17, 1938 'Paten tcd July 18, 1939 V UNITE-o STATES 'rmess roa Maxine ENGINE crnnvnnns wrrn AN nmna LINING Alfred Lesage, Schweinfurt, Germany Application February 17, 1938, Serial No. 190,960 a In Germany February 15 1937 1 Claim. (circa- 203 This invention relates to the cylinder of internal combustion engines and more particularly to cyl inders having an internal surface layer :of a harder metal than the cylinder, this lining being devised .to form the :slide way of the piston reciprocated in the cylinder.-

An object of this invention-is the-method for making the liner in an easy, effective and cheap I way. 1 .10 In lininga casting of light-alloy containing a considerable percentagefof' aluminium with a .melted harder metal or alloy} having a higher melting point with the aim of obtaining an uni-' form and'continuous thin layer the drawback '15 often arises that thealloy with the lower melting point is liquefied as the heat cannot be removed quickly'enough so that the two layers form a new 4 alloy uniform inits hardness and resistance to,

' wearing out, or the harder metal will enter the .20 light-metal to an uncontrollable extent. thereby generating furtherinconv'eniences.

' Thefnew objects will be attained by a method allowing the lining operation to be well and continuously regulated by the gradual formation of 25 the liner. It has been found'that a thin jet of the harder metal when applied to the inside surface of a light-alloy cylinder while advancing on the same in a lengthwise direction and peripherally, viz. along a helical line, will produce a me- 30 tall i'c layer of uniform depth because it cools down more quickly. The thinner the jet of moltenjmetal, themore uniform the layer pro duced, especially when being pressed against and distributed on the inside surface of the cylinder 35 byrcentrifugal force. With theaid of the method according to the present invention it is possible to apply such a thin metal jet in the fo'rmof metallic threads narrowly juxtaposed on the inside surface of a 40 cylinder and tocause the said threads tocombine into a continuous layer which firmly adheres to I v the saidcylinder. E

To this end a rapidly rotated pouring funnel containing the liquid metal and the bottom end,"

45 of which is provided witha smalloutlet nozzle is introduced into the cylinder which'is displaced at a suitable speed along its center line by me-' chanicallydriven means. Under the pressure resulting from gravity th e metal flows out as a '60 thin jetag'ainst the wallgof the cylinder in a helical line, The pressure-maybefincreased by a pressure fluid actin'g'upon the contents of the funnel; The jet may also be applied along a helical line when there is; imparted to the funnel a 65 movement ina lengthwisedirection and a rapid causes the liquid metal to-more strongly adhere to the'cylinder wall. The funnel may also be stationary while the cylinder at the same time has imparted. thereto the said longitudinal and 5 rotary movements in which case the centrifugal force acting on the metal flowing into the cyl in derv will result in the layer applied being dis-' tributed more uniformly and smoothened accordingly. Also thefunnel and the cylinder may be rotated simultaneously, and in general the relative rotation and rectilinear displacement maybe distributed between the funneiand the cylinder in any suitable way and proportion. a e

The accompanying drawing, forming a part'of this specification, by way of example showsan embodiment of the present invention, represent-' ing a device intended for producing the slide sur face for the piston of a light-alloy engine cylinder, the figure representing a. vertical section along the center line of the said device. I

For the production of the harder inside layer the cylinder is fastened to a carrier having the form of a disk 3 which is arranged at the top end of a vertical hollow spindle 4 and rotatably mounted in bearings 5. By means of a pulley 6 fixed on the said spindle 4 and a belt 1 or of a, similar driving appliance the spindle!- may be rotated. Within this spindle there is r'evolubly mounted a shaft dcarrying a pouring funnel s at its upper end which funnel is provided with a slanting outlet spout l0. The lower end-of the with apertures it through which-dropping molten 40 metal, if any, is thrown into the cup H where it collects. I r The device is made use of in the following way: The liquid metal to be applied to the inside surface of the engine cylinder [8 is put into the 46 funnel t rotated by the driving means-i2, i3 and then flowsthrough the outlet l0 against the inside wall of the cylinder l8 while the same is at the same time raised by the appliance l4, 05 so that the liquid metal being poured is applied to 60 the .cylinder wall in helical lines placed narrowly side by side. If a rapid rotation at the same time is imparted 'to the cylinder by the transmission means i, I the. harder metal applied thereto is pressed against the cylinder wall so tained within such a range that the molten metal as to effect a partial fusion of the light metal of the cylinder having a lower melting point so that a connection free from joints and affording a highly satisfactory conductivity for heat will be obtained. By the centrifugal force the juxtaposed helical threads of the molten harder metal will also at once be pressed against one another and combined into a layer uniformly cohering and having about the same thickness throughout. In this way it is possible to produce a comparatively thin layer on the inside wall of the cylinder which layer will by the partial fusion of the metal thereof not, only strongly ad here but also cool down so quickly that the cylinder itself will comprise several concentrical layers of'different metals or alloys with distinct degrees of hardness. By providing the cylinder with heat radiating flanges ll, the temperature of the cylinder during the admission of the molten metal to form the liner may be readily mainwill rapidly solidify; the molten metal will not unduly melt the cylinder and will not be so in.- stantly chilled as to prevent the desired partial melting and the'formation of the bonding alloy.

The relative angular and axial displacements of both the cylinder and the funnel may be chosen tinuously, also a pressure fluid may be caused to act upon the contents of the said funnel. When the process is being carried out, hea may be supplied or carried oif so that the temperature required for the application of the internal liner may be controlled at will.

The material to be used for the slide surface on which the piston runs may be a harder alloy melting at a higher temperature or a hard metal such as cast iron, steel, etc.

In case the inside layer is iron or steel the aluminium is preferably protected from burning; by an atmosphereof 'an inert gas, such as carbonic acid, being formed within and around the cylinder. which gas may at the same time also act as a cooling agent.

I claim: I

The method of making an internal combustion cylinder with a light metal jacket'having radiating fins and a lining of metal of substantially greater hardness and of substantially higher melting point, which comprises the steps of rotating a vertically disposed jacket, projecting a jet of the molten harder metal within and radially of said cylinder jacket, and against the inner periphery of the latter, eifecting relative rotation of said jet and said cylinder, and continuously moving said jet axially of said cylinder, said jet being so fine that the metal therefrom solidifies quickly on the inner surface of the cylinder as a helical strip, and fuses only the inner surface portion of the cylinder jacket on which it is projected, to form a thin-intermediate layer alloyed from said light metal and said harder metal, said jacket being rotated at such high speed, that adjacent turns of said helical strip are levelled off by centrifugal action to form a 

